A two-stage process for the complete silylation of melamine or 2,4-diamino-6-phenyl-1,3,5-triazine a) by reaction with trimethylchlorosilane and triethylamine and b) by reaction with butyllithium and dimethylchlorosilane is known from Inorganic Chemistry Communications, 2002, 5(7), pages 516 to 518. For melamine, this process leads to a yield of 58% in the first stage and to a yield of 55% in the second stage, resulting in an overall yield of ca. 32%. In the case of 2,4-diamino-6-phenyl-1,3,5-triazine, this process leads to a yield of 84% in the first stage and to a yield of 87% in the second stage, resulting in an overall yield of ca. 73%. The yields for both the partial and for the complete silylation are unsatisfactory.
Zhurnal Obshchei Khimii 49(5), 1057-60 (1979) report heating melamine and tetramethyldisilazane (Me2HSi)2NH at 110 to 140° C. for 8h in the presence of ammonium sulfate. This leads to various mixtures of N-bridged SiMe2H triazines in yields of 72.5%. The yield of the silylation is unsatisfactory.
The object of the present invention was therefore to overcome the abovementioned disadvantages.